If I take my daughter in my car, she has to be strapped down in a special seat and cannot move from the seat to be comforted or fed without stopping the car.
If I travel by bus I am expected to balance her on my knee with little protection for her against sudden movements from the bus or other passengers. On the rare occasions that I take her on a bus I would far prefer her to be strapped into a buggy which I can park and hold while the bus goes round corners and brakes sharply for other road users.
Passengers on buses should expect to travel as safely as those in cars or aeroplanes, both of which have strict rules about seat belts, and babies should not be excluded from safe travel on public transport.
Should I have to pay more for my daughter to go on a bus than all the over 60s who get free travel? I don't think so.